townhouse firewall

[abrousse]

New at this and needed a little help. Posted a picture of the firewall in the attic between two units in a townhouse. It's 5/8" gypsum board and fire rated but shouldn't it be on both sides of the studs or is this acceptable? Also do the joints have to be taped?

Thanks to anyone willing to help!

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[Marc]

I don't know about Texas, but next door in Louisiana a townhouse in which the units are intended for individual sale must have a 2-hour firewall between them. What's shown in your photo doesn't even qualify for a one hour firewall.

Marc

[Wayne Gardner]

I recently inspected a 4 unit building built in 1997. Each of the 4 units shared a portion of the attic. When I went up there, I was surprised to find only an OSB wall separating my unit from the rest of the attic.

I checked with a couple other inspectors and the general concensus was the firewall was missing. It didn't seem right though as it was just such a huge oversight. Also, the units were converted to condos/townhomes in 2007 and the builder made significant updates but again, the attic was not changed.

I called the building department and they looked up the address. The inspector spoke as though he was familiar with the property. He said that due to the buildings original designation (apartments?), only a 'draft stop' was required and the conversion in 2007 did not warrant a change in the attic.

Was this building converted? You might want to double check with your local department.

Wayne G

[abrousse]

I recently inspected a 4 unit building built in 1997. Each of the 4 units shared a portion of the attic. When I went up there, I was surprised to find only an OSB wall separating my unit from the rest of the attic.

I checked with a couple other inspectors and the general concensus was the firewall was missing. It didn't seem right though as it was just such a huge oversight. Also, the units were converted to condos/townhomes in 2007 and the builder made significant updates but again, the attic was not changed.

I called the building department and they looked up the address. The inspector spoke as though he was familiar with the property. He said that due to the buildings original designation (apartments?), only a 'draft stop' was required and the conversion in 2007 did not warrant a change in the attic.

Was this building converted? You might want to double check with your local department.

Wayne G

Wayne,

This townhouse was actually built recently in 2007. My opinion is that it doesn't look right, should have gypsum board on this side of the studs as well. Thanks for your help!!

[abrousse]

I don't know about Texas, but next door in Louisiana a townhouse in which the units are intended for individual sale must have a 2-hour firewall between them. What's shown in your photo doesn't even qualify for a one hour firewall.

Marc

Thanks for the info Marc!

[Rocon]

You are right, I have never seen an assembly that only protects the studs on one side. It looks very strange to me even if the wall was rocked before they stood the wall they would have had to finish the backside of the stud. Write it up and if they come back with a UL rating for an assembly I would like to know what it is designated as.

[Darren]

Also, the fire rated assembly needs a fire-rated parapet or the underside of the roof deck needs to be fire-rated.

See 'Dwelling Unit Separation" in your IRC.

[Ed Cope]

Is the attic floor covered with fire rated plywood or some combination of materials that would make the floor/ceiling a rated assembly? My thought is that the builder thought it was more cost effective to create the fire envelope at the ceiling rather than build a fire wall that would have to extend above the roof line.

[Terence McCann]

Is the attic floor covered with fire rated plywood or some combination of materials that would make the floor/ceiling a rated assembly? My thought is that the builder thought it was more cost effective to create the fire envelope at the ceiling rather than build a fire wall that would have to extend above the roof line.

I called a local building department here about no demising wall between condos. The inspector said that he knew of the property and that the ceiling was fire rated and therefore did not need a demising wall. You could pop the hatch however and walk to any of the other suites - the client (older women) walked.

[abrousse]

Is the attic floor covered with fire rated plywood or some combination of materials that would make the floor/ceiling a rated assembly? My thought is that the builder thought it was more cost effective to create the fire envelope at the ceiling rather than build a fire wall that would have to extend above the roof line.

The interesting thing is, when I reference the 2009 IRC, I see that this section has a lot of revisions. There is one section addressing TOWNHOUSES, and another for TWO-FAMILY DWELLINGS. There is mention of having a fire-rated wall OR floor/ceiling in the section for two-family dwellings. However, only a fire-rated wall is mentioned in the townhouse section.

[Bryan]

I do a lot of new construction draw inspections on multi family housing. A lot of it depends on where you are located and what the local fire department requires. On a recent project in Urbana the town houses only required a separation/barrier wall between units and the duplex units required a full fire separation wall with fire proof sheathing, and sealant. For some reason they must think the the town house is safer than a duplex, even when attached to the end of 4 town houses.

Bryan

[Marc]

Alex, perhaps there is a difference in definitions. I've always thought that a 'two family dwelling' was not intended for individual sale and that a condo was. Of course, definitions may be regional.

Marc

[abrousse]

Alex, perhaps there is a difference in definitions. I've always thought that a 'two family dwelling' was not intended for individual sale and that a condo was. Of course, definitions may be regional.

Marc

Got to love those gray areas!!

[Rocon]

Is the attic floor covered with fire rated plywood or some combination of materials that would make the floor/ceiling a rated assembly? My thought is that the builder thought it was more cost effective to create the fire envelope at the ceiling rather than build a fire wall that would have to extend above the roof line.

The interesting thing is, when I reference the 2009 IRC, I see that this section has a lot of revisions. There is one section addressing TOWNHOUSES, and another for TWO-FAMILY DWELLINGS. There is mention of having a fire-rated wall OR floor/ceiling in the section for two-family dwellings. However, only a fire-rated wall is mentioned in the townhouse section.

Remember to quote the right reference. The 2009 IRC being applied to a building that is not under construction right now is a bad move. You need to know when the building was built and under what code the drawings were prepared. In the drawings they will have a wall details section. You will find a UL rating assembly (possibly a GA assembly but they allways reference UL in the GA) that will give you the information you need.

[JeremyDP]

I called a local building department here about no demising wall between condos. The inspector said that he knew of the property and that the ceiling was fire rated and therefore did not need a demising wall. You could pop the hatch however and walk to any of the other suites - the client (older women) walked.

You should call the local housing authority. Here, we have so many towns (and each with their own regulations). I inspected a condo in July that didn't have fire walls in the attic and the four units all had access to the attic. The housing authority said fire walls are only required when the attic space is at least 5000 square feet.

My client told me the builder was going to install a more secure hatch, as I pointed out in the report that this was a security issue.

[Darren]

Is the attic floor covered with fire rated plywood or some combination of materials that would make the floor/ceiling a rated assembly? My thought is that the builder thought it was more cost effective to create the fire envelope at the ceiling rather than build a fire wall that would have to extend above the roof line.

Several questions need to be answered:

Does the town/city enforce the IRC/IBC?

What type of dwelling are we looking at?

There is a big difference between a townhouse, condo or apartments.

The definition of a townhouse is- A single family dwelling unit constructed in a group of three or more attached units in which each unit extends from foundation to roof and with open space on at least two sides.

In New Jersey, a townhouse NOT MORE than 3-stories in height is constructed according to the IRC; more than 3-stories or less than 2 sides open, than it's like a condo and it's constructed according to the IBC.

If it's a true 'Townhouse' and it's built to the IRC, than the following would apply-

Each townhouse shall be considered a separate building and shall be separated by fire-resistance-rated wall assemblies meeting the requirements of section R302 for exterior walls.

The fire resistance-rated wall or assembly separating the townhouses shall BE CONTINUOUS from foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating the enclosed accessory structures.

It goes on to talk about needing a parapet or installing a fire-rating 4 feet each side of the separation wall.

If this dwelling is built to the IBC, there are many, many variations on separation.

I read somewhere (here or IN) where someone stating they were looking at a townhouse that had part of another living space under it; it wasn't a townhouse if there is a living space under it.

You need to know what your looking at before you can determine what's right or wrong.

[abrousse]

Is the attic floor covered with fire rated plywood or some combination of materials that would make the floor/ceiling a rated assembly? My thought is that the builder thought it was more cost effective to create the fire envelope at the ceiling rather than build a fire wall that would have to extend above the roof line.

Several questions need to be answered:

Does the town/city enforce the IRC/IBC?

What type of dwelling are we looking at?

There is a big difference between a townhouse, condo or apartments.

The definition of a townhouse is- A single family dwelling unit constructed in a group of three or more attached units in which each unit extends from foundation to roof and with open space on at least two sides.

In New Jersey, a townhouse NOT MORE than 3-stories in height is constructed according to the IRC; more than 3-stories or less than 2 sides open, than it's like a condo and it's constructed according to the IBC.

If it's a true 'Townhouse' and it's built to the IRC, than the following would apply-

Each townhouse shall be considered a separate building and shall be separated by fire-resistance-rated wall assemblies meeting the requirements of section R302 for exterior walls.

The fire resistance-rated wall or assembly separating the townhouses shall BE CONTINUOUS from foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating the enclosed accessory structures.

It goes on to talk about needing a parapet or installing a fire-rating 4 feet each side of the separation wall.

If this dwelling is built to the IBC, there are many, many variations on separation.

I read somewhere (here or IN) where someone stating they were looking at a townhouse that had part of another living space under it; it wasn't a townhouse if there is a living space under it.

You need to know what your looking at before you can determine what's right or wrong.

Darren,

That's exactly how I read it in the IRC. This building is in fact a "townhouse". It was built in 2007 with that intent. There are 3 units, hence 2 common walls.

Thanks for the input..

[plummen]

Around here anyway a firewall is 2 layers of 5/8" on each side of a stud wall between bays

[Jim Katen]

Around here anyway a firewall is 2 layers of 5/8" on each side of a stud wall between bays

In your area, where and in what type of dwellings is such a fire wall required?

- Jim Katen,

[plummen]

any commercial bay and between any multifamily residential living area ive had the pleasure to set electrical boxes on